The present invention relates to a detent mechanism which imparts a detent in controlling a control portion.
Conventionally, a rotary switch device such as a switch device disclosed in JP-A-5-94922 that is used for various types of automotive control knobs has a detent mechanism which is made up of a control stop surface portion which has ridge portions and root portions which are formed alternately on an inner surface of a casing, a coil spring provided on a rotor side of an interior of the casing and a ball which is biased by the coil spring so as to be brought into abutment with the detent surface portion.
According to the detent mechanism that is configured in this way, when the user rotates a control knob for switch operation, the ball rides over the ridge portion and moves to the root portion to thereby be caused to fall into the root portion as the rotor rotates. Namely, a feedback force given to the control knob changes around a point in time at which the ball rides over the ridge portion, whereby a detent is given in rotation of the control knob.
In the detent mechanism of the conventional rotary switch device that has been described above, since detents are given through mechanical actions, a control stop pattern is limited to a single pattern, and hence, only one type of detent interval and detent strength (click feel) can be given. In this detent mechanism, in order to switch detent intervals and detent strengths, a number of detent mechanisms corresponding to the number of types of switching become necessary, resulting in an increase in size of the switch device.